This is a six week, prospective, randomized, open-label study to evaluate the tolerability of switching from pramipexole, either acutely or by gradual substitution, in Parkinson's disease (PD) patients with motor fluctuations. PD patients with motor fluctuations (e.g. end of dose akinesia, simple on/off fluctuations) who are receiving a stable anti-parkinsonian medication regiment that includes levodopa/carbidopa at a dose of at least 200 mg/day and pramipexole at a does of .75-4.5 mg/day on a TID schedule for at least two weeks will be eligible to enter the study. Patients will be randomized at baseline to acute switch or gradual substitution of ropinirole for pramipexole at a mg ratio of 3x, while continuing on the remainder of their anti-parkinsonian regimen unchanged. The gradual substitution will be executed over three weeks. Following the week 3 visit, the ropinirole dose may be freely tirated to achieve optimal clinical response. Patients will be evaluated at baseline, week 3, and week 6. Each evaluation will include a 24-hour home diary and UPDRS assessments. Week 3 and week 6 evaluations will also include investigator global assessments.